Concerning Pat Buchanan's article blaming everything on Vatican II...
We will never know, but it is possible the Church would now be in serious schism had it not had a Vat II. We might've split into Reform, Conservative and Orthodox wings like Judiasm did. If the Vatican had hard-lined it throughout the 60s & 70s it would've been completely irrelevant to the modern world, much as the Amish.
As it is the Church has bent, but did not break. That is a sign of strength. To have survived the 60s & 70s with all her doctrine intact, including Humane Vitae and the seamless moral dogmas is a good thing, one we can celebrate.
Can one even imagine, in this day of militant Islam, how ugly it would be for the Church if she had maintained her "error has no rights" pre-Vatican II stance on religious freedom? Is there any doubt how the Catholic Church would be compared to Islam, in their intolerance and desire to force their views on people? The Church moved sharply away from favoring theocracies during Vat II, a move that turned out to be prescient.
In short, the numbers might look even worse without Vatican II. When the writer Evelyn Waugh was asked why his being a Christian seemed not to make him one bit nicer, he said something like "you can't imagine how much worse I would be without Christianity".